Dynamics of a population ofCeriodaphnia cornuta Sars (Crustacea: Cladocera) from a seasonal pond in Madurai
Investigation of the dynamics of a population ofCeriodaphnia cornuta indicated that the internal and external phenomena of clutch size and food supply were significant factors influencing population density and other population parameters. The relationships of clutch size with transparency and temperature were attempted. A single period of bisexual reproduction was noticed over a period of 12 months. The mean annual clutch size ranged from one to two eggs. Animals with 3 eggs were far fewer in percentage in the natural habitat. A low positive correlation of r=0·27 was recorded between mean brood size and body length, indicating that small body size naturally restricts the egg laying capacity of the females. The absence of size groups III and IV in the field samples was explained. The population parameters such as finite birth rate (B), instantaneous birth rate (b) population change (r) and death rate (d) were estimated from field data for this cladoceran.